The largest study of the link between cell phone usage and brain tumor …

A freshly published study (PDF) in the British Medical Journal, jointly conducted by four English universities and sponsored by the World Health Organization's International Agency for Research on Cancer (IARC), has found no causal relationship between cell phone usage and glioma, the most common and deadliest of the different types of brain tumors. Nearly 2,000 confirmed glioma sufferers were selected from hospital oncology departments and cancer registries, though 30 percent of the patients died before completing the interview process. After discounting other nonrespondents, 51 percent of the original population, or 966 cases, were included in the study. The demographic makeup of that sample was then replicated in a healthy control group of 1,716 of the Queen's loyal subjects. All of the participants were told that the study concerned risk factors for brain tumors, with no specific mention of cell phones.

While there was an increased number of tumors found on the side of the head glioma patients reported as the side they normally held their phone to, the incidence of tumors on the opposite side was proportionally lower than expected. That's taken by the researchers as a sign that tumor-side cell phone use may have been over-reported, as the overall tumor risk ends up no higher than average. Some observers feel that the results may be skewed because of the deadly nature of these tumors:

"I think they should have waited another couple of years and recruited more people with brain tumours so they could have interviewed them, because the trouble was they went back a few years and the people had died," said Alasdair Philips, director of campaign group Powerwatch.

"If you get a grade four glioma you can die within a year or 18 months of it being diagnosed, and these people are just gone, so they couldn't get their mobile phone history."

That objection sounds valid on the surface, but seems to indicate that Powerwatch relied on news coverage for their information rather than reading the source material. The selection process removed deceased patients from the outset, and furthermore, the research team accounts for this objection in the discussion of potential bias:

As early death is most likely in patients with hugh grade tumors, it is not surprising that participation rates were higher in those with low grade tumors. A bias in these results would occur only if mobile phone use was related to severity of tumor, which was not supported by our analysis, where odds ratios for mobile phone use showed no increased risk for high or low grade tumors

The results of this study support the findings of the majority of current research (though not every study) into the cause and effect relationship between cancer and cell phones. The funding for the project came from the WHO, not from Nokia or Vodaphone, which makes me feel better about the motives behind the research. Dr Kat Arney, science information officer at Cancer Research UK, said "This is the biggest and most thorough study into mobile phones and glioma so far, and it adds to the growing evidence that there is no link. Although we still don't know about the very long-term effects of phone use, these results are reassuring for everyone with a mobile." So I guess it's safe to upgrade to that 1,500 minute plan now. Caesar will be so sick of my voice by next week, it's not even funny.